Method and device for manufacturing a twisted yarn in an integrated spin-twisting process according to the two-for-one twisting method from dissolved fiber material

Abstract

In a method for manufacturing a twisted yarn by an integrated spinning-twisting process a vacuum is generated within the spindle rotor. Individual staple fibers are fed by vacuum to at least two rotor spinning devices positioned within the spindle rotor in which individual spun yarns are spun from the individual staple fibers. The individual spun yarns are gathered and guided in a first direction through the spindle rotor in order to subject the individual spun yarns to a first twist. The twisted yarn is guided in a second direction counter to the first direction to a centering element positioned above the rotor spinning devices whereby the twisted yarn forms a rotating yarn balloon about the spindle rotor. The twisted yarn is then wound onto a bobbin. Feeding of the individual staple fibers includes supplying them essentially in a radially inward direction through a fiber material feed tube to an annular space, positioned at the spindle rotor coaxially to a central axis of the yarn balloon, and from the annular space through respective fiber material supply channels to the at least two rotor spinning devices. The envelope of the yarn balloon extends through the annular space and the individual staple fibers pass through the yarn balloon. In the step of guiding the twisted yarn in a second direction counter to the first direction the twisted yarn is routed through a yarn guide element rotating with the yarn balloon.

What we claim is: 
     
       1. A method for manufacturing a twisted yarn by an integrated spinning-twisting process; said method comprising the steps of: generating a vacuum within a rotating spindle rotor;   dissolving fiber material to produce individual staple fibers;   feeding the individual staple fibers by means of said vacuum to at least two rotor spinning devices positioned within the spindle rotor;   spinning in the rotor spinning devices individual spun yarns from the individual staple fibers;   gathering the individual spun yarns from the rotor spinning devices and guiding the individual spun yarn in a first direction through the spindle rotor in order to subject the individual spun yarns to a first twist to form a twisted yarn;   guiding the twisted yarn in a second direction counter to said first direction to a centering element positioned above the rotor spinning devices whereby the twisted yarn forms a rotating yarn balloon about the spindle rotor;   winding the twisted yarn onto a bobbin;   wherein said step of feeding the individual staple fibers includes the steps of supplying essentially in a radially inward direction relative to the axis of rotation of said spindle rotor the individual staple fibers through a fiber material feed tube to an annular space, positioned at the spindle rotor coaxially to a central axis of the yarn balloon, and from the annular space through respective fiber material supply channels to the at least two rotor spinning devices, wherein the envelope of the yarn balloon extends through the annular space and wherein the individual staple fibers pass through the yarn balloon; and   wherein said step of guiding the twisted yarn in a second direction counter to said first direction includes the step of routing the twisted yarn through a yarn guide element rotating with the yarn balloon.   
     
     
       2. A method according to claim 1, further including the step of positioning the outlet opening of the fiber material feed tube into the annular space and the inlet opening of the fiber material supply channel into the annular space radially opposite one another. 
     
     
       3. A method according to claim 1, further including the step of positioning the outlet opening of the fiber material feed tube into the annular space so as to be spaced in the circumferential direction of the annular space from the inlet opening of the fiber material supply channel into the annular space in a direction of rotation of the yarn balloon. 
     
     
       4. A spinning and twisting device comprising: a spindle rail;   at least one spindle comprising a spindle rotor rotatably connected to said spindle rail, an interior casing surrounding said spindle rotor coaxially, and an exterior housing enclosing said interior casing;   said spindle rotor comprising a hollow spindle axle and a yarn guide channel connected to said hollow spindle axle so as to extend radially outwardly from said hollow spindle axle;   a centering element positioned above said hollow spindle axle on an extension of the axis of rotation of said hollow spindle axle;   at least two rotor spinning devices positioned within said interior casing;   a device for feeding individual staple fibers to said at least two rotor spinning devices, wherein the individual staple fibers are spun to spun yarns in the rotor spinning devices, guided through said hollow spindle axle and through said yarn guide channel to the exterior of said interior casing and to said centering element while forming a yarn balloon between said yarn guide channel and said centering element;   a fiber material supply channel positioned within said interior casing for each one of said rotor spinning devices for feeding fiber material to each one of said rotor spinning devices;   each one of said fiber material supply channels having an inlet opening at the outer wall of said interior casing;   a fiber material feed tube located in said exterior housing for each one of said fiber material supply channels for feeding fiber material to each one of said fiber material supply channels, said fiber material feed tubes having an outlet opening positioned at an inner wall of said exterior housing;   a spun yarn removal tube for each one of said rotor spinning devices for guiding the spun yarns from said rotor spinning devices to said hollow spindle axle where a twisted yarn is formed from the spun yarns;   a rotating component arranged coaxially to said hollow spindle axle between said interior casing and said exterior housing and rotating with the yarn balloon, said rotating component comprising an integral yarn guide element for guiding at least over a portion of the height of the yarn balloon the twisted yarn;   said rotating component comprising two annular members positioned opposite one another so as to delimit therebetween an annular space into which said inlet opening of said fiber material supply channels and said outlet opening of said fiber material feed tubes open; and   said rotating component further comprising at least one connecting element for connecting said two annular members, said connecting elements extending through said annular space, wherein said integral yarn guide element extends through one of said at least one connecting elements.   
     
     
       5. A device according to claim 4, wherein said inlet openings of said fiber material supply channels are spaced in the circumferential direction of the annular space from the inlet opening of the fiber material supply channel into the annular space in a direction of rotation of the rotating component. 
     
     
       6. A device according to claim 4, wherein three of said connecting elements are provided. 
     
     
       7. A device according to claim 4, wherein between said inner wall of said exterior housing and said annular members first gaps are formed and wherein between said outer wall of said interior casing and said annular members second gaps are formed, said device further comprising gap seals in the form of labyrinth seals for said first and second gaps, wherein said annular space is subjected to a vacuum. 
     
     
       8. A device according to claim 7, wherein said labyrinth seals in a circumferential direction of said annular space have return threads of opposite pitch orientation relative to said annular space. 
     
     
       9. A device according to claim 4, wherein a width of said at least one connecting element in a circumferential direction of said rotating component is greater than half a length of a longest individual staple fiber within the supplied fiber material. 
     
     
       10. A device according to claim 4, wherein said annular space is positioned at a maximum radial extension of said interior casing. 
     
     
       11. A device according to claim 4, wherein: said rotating component is a pot fixedly connected to said spindle rotor;   said annular members are positioned at an upper end of said pot; and   said yarn guide element extends through a wall of said pot upwardly into one of said at least one connecting elements.   
     
     
       12. A device according to claim 4, wherein: said rotating component is a wheel of a conical shape rotatably connected above said spindle rotor in the area of said centering element;   said conical shape has a tip that faces away from said interior casing;   said wheel has an outer edge that overlaps the upper edge of said interior casing;   said annular members connected to said outer edge;   said yarn guide element being in the form of a yarn guide tube extending from said outer edge through one of said at least one connecting elements to said centering element; and   said exterior housing comprising a stationary cover positioned above said wheel.